Dr Barnes' $25 billion private collection of art and arboretum.

The headquarters of the Fraternitas Rosae Crucis, complete with Rosicrucian pyramids, all in the Pennsylvania woods.

This might just be the TARDIS of bookstores.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

The oldest surviving botanic garden in the United States.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

In which a local geological marvel becomes a quaint roadside attraction.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

This eerily well-preserved coal town was saved from destruction by a Sean Connery movie.

Huge masonic hall in Philadelphia with lavishly themed rooms.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

A modern ghost town whose inhabitants were driven away by the growth of nuclear power.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

An abandoned stretch of highway, deteriorating next to the operational one.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

Mysterious rocks that ring musically when struck.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

World's first "penitentiary," meant to be humane, drove men insane.